4.1 Classifying Rocks

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Vocabulary

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inorganic-something that is not made out of living things
crystal-The repeating pattern of a mineral particle forms a solid
element-a substance that has only one kind of atom
compound-two or more elements combined
Mohs hardness scale-a scale that ranks ten minerals from hardest to softest
streak-the color of a minerals powder
luster-how the mineral reflects the light
cleavage-the way a mineral breaks apart
fracture-how a mineral breaks
fluorescence-a property some minerals have that they glow under ultraviolet light

Outline

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4.1 Classifying rocks

1. What is a mineral?
   • Naturally occurring
     • a mineral must be naturally occurring
   • Inorganic
     • a mineral must be inorganic
     • means not from the materials once part of a living thing
   • Solid
     • a mineral must be a solid
   • Crystal structure
     • the patterns of a mineral repeat over and over again
   • Definite Chemical Composition
     • a mineral must have a definite chemical composition
     • means a mineral contains a certain element
2. **

Identifying minerals

• Hardness

* each mineral has different hardness

• they are rated by the Mohs hardness scale
• Color
  • each mineral has a different color
• Streak
  • the color of a mineral's powder
• Luster
  • A mineral reflects light in a different way
• Density
  • each mineral has a different weight in the same volume
• Crystal Systems
  • each mineral has a different crystal structure
• Cleavage and fracture
  • a mineral has a different color when broken
  • it also breaks in a different way
• Special properties
  • some minerals have amazing properties